In the existing SMD LED manufacturing, products generally adopt the PLCC4 structure (such as 3528, 2121, 1010, etc.). However, the above structure exists individually. In actual production, it can only be attached one by one. As such, the production efficiency is low and maintenance is difficult. Especially in the production of LED display screens, the number of LEDs used is usually in the order of tens of thousands or even millions. When producing small-sized products, such as format 1.0 mm*1.0 mm and below, difficulty of production will be multiplied, mechanical strength of the product will be very low, damage will easily happen under action of external force, production efficiency will be low, and requirement for mounting equipment will be high. For the one by one mounting problem, the applicant has adopted the form of a packaging module, i.e. multiple sets of RGB-LED chips are packaged on the same module, as disclosed in Chinese Patent applications with Publication Nos. CN106847801A and CN106847800A. However, the above Patent applications may have some problems in actual production. As shown in FIG. 1, in the packaging module, since the LED light is diffused, light emitted from adjacent light-emitting units will be interfered. Since a single light-emitting unit emits light formed from a mixture of three kinds (RGB) of chips, if the light from adjacent light-emitting units causes interference, it will directly affect the light that is mixed, thereby affecting the definition and sharpness. In addition, when using this kind of packaging module, the number of solder pads on the back of the module will be very large. For example, for a four-piece RGB-LED packaging module, each having four sets of RGB-LED chips, the number of back solder pad is up to 16. In case of a small space, this greatly increases the difficulty of PCB design and the difficulty of soldering.
Therefore, the prior art has yet to be improved and developed.